Electric power has greatly improved the life of human being ever since its discovery and made huge progress of material civilization possible. Nowadays people rely heavily on the electric power in every aspect of life, and the demand of electric power is enormous. Mankind has constantly endeavored all kinds energy exploitation and development to get electric power. The most commonly adopted power generation approach at present is through power generators.
A power generator mainly comprises a stator and a rotor, and corresponding coils and magnets located respectively on the stator and rotor. When the rotor spins against the stator, according to the induction effect discovered by British physicist Faraday, the stator and rotor provide cutting of the magnetic lines to generate current.
R.O.C. patent No. M326582 discloses a direct-driven external rotor power generator which comprises a shaft, a rotor casing, a plurality of permanent magnets, a stator support casing, a stator coil and a rotor back iron ring. The shaft drives the rotor to spin. The magnets spin against the coil, and the coil is induced to generate alternating current.
The aforesaid technique adopts a traditional power generation structure, i.e., the stator is stationary, and the rotor spins to cut the magnetic lines of the coil and magnets to generate electric current. Such a structure has a disadvantage, namely the amount of power generation fully depends on the spinning speed input by the rotor. To get more power output more power is required to drive the rotor to spin at faster speeds. To remedy this drawback, a technique able to maintain substantial output power under a limited rotor spinning speed has been developed. It provides a stator spinning against the rotor.
R.O.C. publication No. 200409438 discloses a high efficiency power generator which includes a rotor and a stator. The rotor is held in the stator. The rotor and stator are driven respectively by its own power driving mechanism to spin independently about the same spindle but in opposite directions.
R.O.C. publication No. 201027884 also discloses a power generator which includes a coil portion and a magnetic portion that spin against each other in opposite directions.
The two prior arts mentioned above have the rotor and stator (i.e. coil and magnetic portion) that spin independently to increase the relative spinning speed and power generation amount. But the driving mechanism is formed by vanes that makes the power generator too bulky.
R.O.C. publication No. 201025796 discloses a power generation apparatus with improved power generation efficiency which has a power output device and a power generator set. The power generator set includes a differential gear set, a magnetic rotor and an armature rotor. The magnetic rotor has magnets on the surface. The armature rotor has armatures corresponding to the magnets. Through the differential gear set the magnetic rotor and armature rotor spin against each other in opposite directions.
The aforesaid technique makes the armature rotor and magnetic rotor spinning against each other in the opposite directions via the differential gear set to get greater amount of current. It adopts a bevel gear as the driving mechanism that takes a lot of space and also requires more elements. As a result, the structure is more complex, and repairs and maintenance also are more difficult.